Infections of the respiratory system Flashcards
What is pneumonia
‘chest infection’, refers to lung inflammation
associated with consolidation or infiltrates secondary
to infection.
what are the different types of pneumonia?
- Community-acquired pneumonia (CAP) refers to
patients with a pulmonary parenchymal infection
who present with symptoms of an acute infection
from the community - Hospital-acquired pneumonia (HAP) presents after
at least 48 hours in a hospital setting
3.Healthcare-associated pneumonia (HCAP) refers
to pneumonia that develops in patients who
reside in nursing homes, long-term care facilities
or haemodialysis centres or who have had recent
chemotherapy
- Aspiration pneumonia is caused by inhalation
of contents (e.g. vomitus) in patients with
altered mental status/stroke, causing lung
injury and subsequent infection; treatment is
with intravenous antibiotics and supportive
care - Ventilator-assisted pneumonia is likely to occur
48–72 hours after endotracheal intubation
6.Pneumocystis jirovecii pneumonia (previously
known as Pneumocystis carinii pneumonia or
PCP) is caused by an opportunistic infection in
HIV patients; diagnosis is made by identifying
the organism in sputum; treatment is with
co-trimoxazole
- Atypical pneumonia (e.g. mycoplasma)
What are the typical causes of pneumonia
- Strep. pneumoniae. the most common cause of CAP. Elderly and immunocompromised
- Staph.aureus. occurs in infulenza infection
- Klebsiella pneumoniae. Alcoholics and diabetics
- Legionella. Air conditioning or travel history to a foreign country. (hyponatraemia and deranged LFT)
- Mycoplasma. erythema multiforme, cold autoimmune haemolytic anaemia. Treat with erythromycin.
Strep. pneumoniae common in?
in CAP. Elderly and immunocompromised
Staph.aureus is associated with?
influenzas infection
Klebsiella pneumoniae. is associated with?
Alcoholics and diabetics
Legionella pneumonia is associated with?
Air conditioning or travel history to a foreign country. (hyponatraemia and deranged LFT)
Mycoplasma pneumonia is associated with?
erythema multiforme, cold autoimmune haemolytic anaemia. Treat with erythromycin.
Clinical features of pneumonia?
Fever
Cough with purulent sputum which may be blood-stained
Shortness of breath
Malaise, loss of appetite and myalgia
is the lower respiratory tract sterile?
The lower respiratory tract typically remains sterile
because of pulmonary defence mechanisms
Investigations of pneumonia?
CXR
Bloods: FBC, U&E, LFT
Sputum, MS&C
urinary antigen for Legionella
serology for mycoplasma
What is CRUB-65?
tool in predicting
30-day mortality in community-acquired
pneumonia.
•Confusion (abbreviated mental test score <8) • Urea >7 • Respiratory rate >30 • BP <90 OR DBP <60 (either one scores one point; if both are present, the score remains one point for both) • 65 – Age ≥65
Management of CAP penumonia
- CURB-65 score. 0-1: Amoxicillin 500mg TDS OR clarithromycin
500mg BD for 5 days (oral)
2.If CURB-65 score 2, inpatient treatment
(moderate)
• Amoxicillin 500mg tds AND clarithromycin
500mg bd for 7 days (oral or IV)
3.If CURB-65 score ≥3, consider ITU admission (severe) • Co-amoxiclav 1.2g TDS IV AND clarithromycin 500mg BD IV for 7 days • Consider ICU involvement
Management of HAP penumonia
Offer antibiotic therapy as soon as
possible, and certainly within 4 hours of
diagnosis
Consider a course of antibiotics for 5–10
days in accordance with local hospital
protocol for HAP
What is lung abscess
necrotic lung tissue and cavity
formation secondary to infection.
risk factor of lung abscess
alcohol excess, diabetes, cystic fibrosis and
risk factors for aspiration are at much greater risk of
developing an abscess
Primary disease for lung abscess
Existing pneumonia or lung disease
Untreated pneumonia can cause abscess
formation
Secondary disease for lung disease
Aspiration
Alcoholics
Septic emboli from right-sided infective
endocarditis
clinical feature of lung abscess
Swinging fevers
Night sweats
Productive cough with purulent sputum
Management o lung abscess
Diagnosis is made on CXR, CT and sputum culture.
Bronchoscopic aspirates can be assessed for
organisms, and may also provide symptomatic relief.
Treat with IV broad-spectrum antibiotics; the majority
of cases will resolve. If refractory to medical therapy,
surgical resection may be considered.
What is tuberculosis?
granulomatous
disease caused by mycobacteria, the most common
of which is M. tuberculosis.
Can have both pulmonary and extra-pulmonary signs
name some clinical features of TB
expectorant cough fever haemoptysis malaise weight loss
name some extra-pulmonary features of TB
arthritis meningitis pott spin erythema nodosum finger clubbing
what are the risk factors of TB
alcoholics
homelessness
immunocompromised
what is someone infected with TB
mycobacteria is engulfed in droplets, and replicates within alveolar macrophages
which part of the lung does TB commonly affect?
TB typically affects the apical and upper
zones of the lungs. The reason for this is not
completely understood, but it is thought to
occur here because these parts of the lungs
have better air flow and reduced lymphatic
drainage.
name some investigations of TB
CXR
sputum sample. 3 of them, one must be early morning. NAAT should be used
Blood tests
MAntoux (tuberculin) skin test
which stain is used to look for acid-fast bacilli in TB
Ziehl-Neelsen
what is the name of culture used in TB
Löwenstein–Jensen medium, and it takes 4–8 weeks
Management of TB
isolate the patient
2 months: isoniazid, rifampicin, pyrazinamide, ethambutol
4 further months of: isoniazid, rifampicin
side effect of isoniazid
soniazid (Iso-neuro-zid) – peripheral
neuropathy (supplement with Vit B6 to
prevent), agranulocytosis, hepatitis
side effect of ethambutol
(Eye-thambutol) – optic
neuritis, renal impairment
side effect of pyrazinamide
Pyrazinamide (Pyr-ouch-zinamide) –
hyperuricaemia causing gout, myalgia and
hepatitis
side effect of rifampicin
Rifampicin (Red-famipicin) – reddish
orange secretions, hepatitis
what is aspergillus?
a group of fungal moulds that may precipitate lung disease.
what are the cutaneous features of aspergillosis
cellulitis
ulcers with necrotic centres
treat with voriconazole
what is an aspergilloma?
also known as a mycetoma, is
essentially a fungal ‘ball’ that is located in a lung
cavity, usually secondary to another disease
process such as TB
what is the treatment of aspergilloma?
surgical removal of the
aspergilloma, with long-term itraconazole
what is Allergic bronchopulmonary
aspergillosis (ABPA)
characterised by respiratory difficulty caused
by a hypersensitivity reaction to Aspergillus spp., often
seen in patients with a history of atopy.
what is ABPA common in?
asthma or cystic fibrosis
treatment of ABPA
1.oral CORTICOSTEROIDS and
ITRACONAZOLE
2 Steroid therapy may be required for up
to 6 months
3 Prescribe bronchodilator treatment for
asthma and manage cystic fibrosis as
per recommendations. SABA, LRA
